1999 DODGE NEON belt

ENGINE THERMOSTAT
The engine thermostat is located on the front of
the engine (radiator side) in the thermostat housing/
engine outlet connector. The thermostat has an air
bleed (vent) located in the flange and a O-ring for
sealing incorporate on it. There is a relief in the ther-
mostat housing/outlet connector for the O-ring.
WATER PUMP
The water pump has a diecast aluminum body and
housing with a stamped steel impeller. The water
pump bolts directly to the block (Fig. 4). Cylinder
block to water pump sealing is provided by a rubber
O-ring. The water pump is driven by the timing belt.
Refer to Group 9, Engine section for component
removal to access the water pump.
NOTE: The water pump on all models can be
replaced without discharging the air conditioning
system.
COOLANT
The cooling system is designed around the coolant.
The coolant must accept heat from engine block
metal and in the cylinder head area near the exhaust
valves. Then coolant carries this heat to the radiator
where the tube/fin assemblies of these components
can give off the heat to the air.
MopartAntifreeze or the equivalent is recom-
mended for optimum cooling performance and corro-
sion protection when mixed to a freeze point of -37É C
(-35É F).
COOLANT REPLACEMENT
Refer to Group 0, Lubrication and Maintenance for
schedule.
COOLING SYSTEM PRESSURE CAP
The cooling system is equipped with a pressure cap
that releases pressure at some point within a range
of 97-124 kPa (14-18 psi) (Fig. 5).
The system will operate at higher than atmo-
spheric pressure, which raises the coolant boiling
point, allowing increased radiator cooling capacity.
AUTOMATIC TRANSMISSION OIL COOLER
Oil coolers are internal oil to coolant type, mounted
in the radiator lower tank (Fig. 6). Rubber oil lines
feed the oil cooler and the automatic transmission.
Use only approved transmission oil cooler hose. Since
these are molded to fit space available, molded hoses
are recommended. Tighten Oil Cooler Hose Clamps
to 2 N´m (18 in. lbs.).
RADIATOR
The radiator is a down-flow type (vertical tubes)
with design features that provide greater strength,
as well as sufficient heat transfer capabilities to keep
the engine satisfactorily cooled (Fig. 6).
ENGINE BLOCK HEATER
The engine block heater is available as an optional
accessory. The heater, operated by ordinary house
current (110 Volt A.C.) through a power cord and con-
nector behind the radiator grille, provides easier
engine starting and faster warm-up when vehicle is
operated in areas having extremely low tempera-
tures.
Fig. 4 Water Pump
Fig. 5 Cooling System Pressure Cap
PLCOOLING 7 - 3
GENERAL INFORMATION (Continued)

WATER PUMP
The water pump body is made of aluminum with a
steel impeller. The water pump is bolted to the frontof the block, and driven by the timing belt. The water
pump is the heart of the cooling system, pumping the
coolant through the engine block, cylinder head,
heater core, and radiator.
NOTE: The water pump on all models can be
replaced without discharging the air conditioning
system.
Fig. 8 Hose Clamp Tool
7 - 6 COOLINGPL
DESCRIPTION AND OPERATION (Continued)

COOLING SYSTEM DIAGNOSIS CONT.
CONDITION POSSIBLE CAUSES CORRECTION
INADEQUATE AIR CONDITIONER
PERFORMANCE (COOLING
SYSTEM SUSPECTED)1. Radiator and/or air conditioning
condenser is restricted, obstructed
or dirty.1. Remove restriction and/or clean
as necessary.
2. Electric radiator fan not operating
when a/c is on.2. Refer to appropriate Powertrain
Diagnostic Procedures manual for
operation of the DRB scan tool.
repair as necessary.
3. Engine is overheating ( heat may
be transferred from radiator to A/C
condenser. High underhood
temperature due to engine
overheating may also transfer heat
to A/C components).3. Correct overheating condition.
Refer to Group 7, Cooling.
INADEQUATE HEATER
PERFORMANCE.1. Has a diagnostic trouble code
(DTC) been set?1. Refer to On-Board Diagnostic in
Group 25, and replace thermostat if
necessary.
2. Coolant level low. 2. Refer to testing cooling system
for leaks in this section. Repair as
necessary.
3. Obstructions in heater hose
fittings at engine.3. Remove heater hoses at both
ends and check for obstructions.
Repair as necessary.
4. Heater hose kinked. 4. Locate kinked area and repair as
necessary.
5. Water pump is not pumping
coolant to heater core. When the
engine is fully warmed up, both
heater hoses should be hot to the
touch. The accessory drive belt
may be slipping causing poor water
pump operation.5. Refer to water pump in this
group. Repair as necessary. If
slipping belt is detected, refer to
accessory drive belts in this group.
Repair as necessary.
HEAT ODOR 6. Various heat shields are used at
certain drive line components. One
or more of these shields may be
missing.6. Locate missing shields and
replace or repair as necessary.
PLCOOLING 7 - 11
DIAGNOSIS AND TESTING (Continued)

ENGINE THERMOSTAT TESTING
The thermostat is operated by a wax filled con-
tainer (pellet) which is sealed. When heated coolant
reaches a predetermined temperature the wax pellet
expands enough to overcome the closing spring and
water pump pressure, which forces the valve to open.
Coolant leakage into the pellet will cause a thermo-
stat to fail open. Do not attempt to free up a thermo-
stat with a screwdriver.The thermostat that opens too soon type failure
mode is included in the on-board diagnosis. The
check engine light will not be lit by an open too soon
condition. If it has failed open, a diagnostic trouble
code (DTC) will be set. Do not change a thermostat
for lack of heater performance or temperature gauge
position, unless a DTC is present. See Diagnosis for
other probable causes. Thermostat failing shut is the
normal long term mode of failure, and normally, only
on high mileage vehicles. The temperature gauge will
indicate this. Refer to Diagnosis in this section.
ACCESSORY DRIVE BELT DIAGNOSIS
CONDITION POSSIBLE CAUSE CORRECTION
INSUFFICIENT ACCESSORY
OUTPUT DUE TO BELT SLIPPAGE1. Belt too loose. 1. Adjust belt tension.
2. Belt excessively glazed or worn. 2. Replace and tighten as specified.
BELT SQUEAL WHEN
ACCELERATING ENGINE1. Belts too loose. 1. Adjust belt tension.
2. Belts glazed. 2. Replace belts.
BELT CHIRP AT IDLE 1. Belts too loose. 1. Adjust belt tension.
2. Foreign material imbedded in
belt.2. Replace belt.
3. Non-uniform belt. 3. Replace belt.
4. Misaligned pulley(s). 4. Align accessories.
5. Non-uniform groove or eccentric
pulley.5. Replace pulley(s).
BELT ROLLED OVER IN GROOVE
OR BELT JUMPS OFF1. Broken cord in belt. 1. Replace belt.
2. Belt too loose, or too tight. 2. Adjust belt tension.
3. Misaligned pulleys. 3. Align accessories.
4. Non-uniform grooves or eccentric
pulley.4. Replace pulley(s).
PLCOOLING 7 - 13
DIAGNOSIS AND TESTING (Continued)

COOLING SYSTEMÐREFILLING
First clean system to remove old glycol, see Cooling
System Cleaning.
Fill system using antifreeze described in Coolant
section. Fill 50 percent of capacity with 100 percent
glycol. Then complete filling system with water.
Continue filling system until full, this provides bet-
ter heater performance.Be careful not to spill
coolant on drive belts or the generator.
Fill coolant reserve system to at least the FULL
mark with 50/50 solution. It may be necessary to add
coolant to the reserve tank after three or four warm-
up/cool down cycles to maintain coolant level between
the FULL and ADD marks; if any trapped air was
removed from the system.
REMOVAL AND INSTALLATION
WATER PUMP
REMOVAL
(1) Raise vehicle on a hoist. Remove right inner
splash shield.
(2) Remove accessory drive belts and power steer-
ing pump. Refer to Accessory Drive Belt service in
this section.
(3) Drain cooling system. Refer to Cooling System
Draining in this section.
(4) Support engine from the bottom and remove
right engine mount.
(5) Remove power steering pump bracket bolts and
set pump and bracket assembly aside. Power steering
lines do not need to be disconnected.
(6) Remove right engine mount bracket.
(7) Remove timing belt and timing belt tensioner.
Refer to Group 9, Engine for procedure.
(8) Remove camshaft sprockets and inner timing
belt cover. Refer to Group 9, Engine for procedure.(9) Remove water pump attaching screws to engine
(Fig. 14).
INSTALLATION
(1) Install new O-ring gasket in water pump body
O-ring groove (Fig. 15). Use small dabs of Mopart
Silicone Rubber Adhesive Sealant around the water
pump body to secure O-ring in place during installa-
tion.
CAUTION: Make sure O-ring gasket is properly
seated in water pump groove before tightening
screws. An improperly located O-ring may cause
damage to the O-ring and cause a coolant leak.
(2) Assemble pump body to block and tighten
screws to 12 N´m (105 in. lbs.). Pressurize cooling
system to 15 psi with pressure tester and check
water pump shaft seal and O-ring for leaks.
(3) Rotate pump by hand to check for freedom of
movement.
(4) Install inner timing belt cover.
(5) Install timing belt. Refer to Group 9, Engine
for procedures.
(6) Install right engine mount bracket and engine
mount. Refer to Group 9, Engine for procedure.
(7) Fill cooling system. SeeCooling System
Refilling.
(8) Install power steering pump and accessory
drive belts, Refer to Accessory Drive Belts, in this
section.Fig. 13 Draining Cooling System
Fig. 14 Water Pump
Fig. 15 Water Pump Body
PLCOOLING 7 - 17
SERVICE PROCEDURES (Continued)

must be replaced withonlythe recommended part
for adequate strength, performance and safety.
(1) To remove fan from motor shaft, bench support
the motor and motor shaft, while removing the fan
retaining clip, so that the shaft and motor will not be
damaged by excessive force.Surface burr removal
may be required to remove fan from motor
shaft (Fig. 25).Do not permit the fan blades to
touch the bench.
(2) To install fan on motor shaft, slide the fan over
shaft. Support motor and shaft as above while
installing fan retaining clip.
INSTALLATION FAN MODULE
(1) Install module to radiator. Torque shroud to
radiator fasteners to 7.5 N´m (65 in. lbs.).
(2) Connect fan motor lead.For wiring diagrams
of fan motor systems Refer to 8W Wiring Dia-
grams.
ELECTRIC FAN MOTORÐSERVICE
WARNING: Do not disassemble the fan motor from
the support bracket.
Electric fan motor is serviced as an assembly with
the fan module.
FAN SHROUD
Some fan shrouds are equipped with flapped doors
to prevent the shroud from restricting air flow at
high speeds.
All vehicles have fan shrouds to improve fan air
flow efficiency.
The shroud supports the electric fan motor and
fan. For removal and installation procedures, refer to
radiator removal in this Section.
ENGINE BLOCK HEATER
REMOVAL
(1) Drain coolant from radiator and cylinder block.
Refer to Cooling System Drain, Clean, Flush and
Refill of this section for procedure.
(2) Detach power cord plug from heater.
(3) Loosen screw in center of heater. Remove
heater assembly.
INSTALLATION
(1) Thoroughly clean core hole and heater seat.
(2) Insert heater assembly with element loop posi-
tionedupward.
(3) With heater seated, tighten center screw
securely to assure a positive seal.
(4) Fill cooling system with coolant to the proper
level, vent air, and inspect for leaks. Pressurize sys-
tem with Radiator Pressure Tool before looking for
leaks.
ACCESSORY DRIVE BELTS
AIR CONDITIONING COMPRESSOR AND
POWER STEERING PUMP
(1) Loosen the power steering pump locking bolts
A and B and pivot bolt C (Fig. 26) to remove and
install belt and/or adjust belt tension.
(2) Using a 1/2º breaker bar, adjust belt tension by
applying torque to the square D hole on the power
steering pivot bracket. Adjust tension to specification
given in Belt Tension Chart.
(3) Tighten in order, first tighten locking bolt A to
27 N´m (20 ft. lbs.) then, bolt B to 27 N´m (20 ft. lbs.)
Then pivot bolt C to 54 N´m (40 ft. lbs.).
GENERATOR BELT
(1) Loosen pivot bolt E then locking nut F and
adjusting bolt G (Fig. 27) to remove and install belt
and/or adjust belt tension.
(2) Tighten adjusting bolt G, adjust belt tension to
specification shown in Belt Tension Chart.
(3) Tighten pivot bolt E to 54 N´m (40 ft. lbs.).
Locking nut F to 54 N´m (40 ft. lbs.).
CLEANING AND INSPECTION
WATER PUMP
Replace water pump body assembly if it has any of
these defects:
(1) Cracks or damage on the body.
(2) Coolant leaks from the shaft seal, evident by
coolant traces on the pump body.
(3) Loose or rough turning bearing.
(4) Impeller rubs either the pump body or the
engine block.
Fig. 25 Servicing Radiator Fan
PLCOOLING 7 - 21
REMOVAL AND INSTALLATION (Continued)

(5) Impeller loose or damaged.
(6) Sprocket or sprocket flange loose or damaged.
ACCESSORY DRIVE BELT INSPECTION
Belt replacement under any or all of the following
conditions is required, excessive wear, frayed cords or
severe glazing.
Poly-V-Belt system may develop minor cracks
across the ribbed side. These minor cracks are con-
sidered normal and acceptable. Cracks parallel are
not (Fig. 28).
NOTE: Do not use any type of belt dressing or
restorer on Poly-V-Belts.
COOLING SYSTEM CAP
Hold the cap in your hand,right side up(Fig. 29).
The vent valve at the bottom of the cap should open
with a slight pull. If the rubber gasket has swollen,
preventing the valve from opening, replace the cap.
If any light can be seen between vent valve and
the rubber gasket, replace the cap.Use only a
replacement cap that has a spring to hold the
vent shut.
A replacement cap must be of the type designed for
coolant reserve systems. This design ensures system
pressurization.
CLEANING COOLING SYSTEM
Drain cooling system (see:Draining Cooling Sys-
tem) and refill with clean water (see:Refilling
Fig. 26 Power Steering Pump Adjustment
BELT TENSION CHART
ACCESSORY
DRIVE BELTGAUGE TORQUE
Power Steering
Pump and A/C
CompressorNew 135 lb. 121 N´m (90 ft.
lbs.)
Used 100 lb. 81 N´m 60 ft.
lbs.)
Generator New 135 lb. Gauge
adjustment
method only Used 100 lb.
Fig. 27 Generator Adjustment
Fig. 28 Drive Belt Wear Pattern
7 - 22 COOLINGPL
CLEANING AND INSPECTION (Continued)

Cooling System). Run engine with radiator cap
installed until upper radiator hose is hot. Stop
engine and drain water from system. If water is
dirty, fill, run and drain system again until water
runs clear.
RADIATOR FLUSHING
Drain cooling system and remove radiator hoses
from engine. Install suitable flushing gun in radiator
lower hose. Fill radiator with clean water and turn
on air in short blasts.
CAUTION: Internal radiator pressure must not
exceed 138 kPa (20 psi) as damage to radiator may
result. Continue this procedure until water runs
clear.
ENGINE FLUSHING
Drain radiator (see:Cooling System Draining)
and remove hoses from radiator. Remove engine ther-
mostat and reinstall thermostat housing. A gasket
may be needed to seal the housing to cylinder head
because the seal is part of thermostat. Install suit-
able flushing gun to thermostat housing hose. Turn
on water, and when engine is filled, turn on air, but
no higher than 138 kPa (20 psi) in short blasts. Allowengine to fill between blasts of air. Continue this pro-
cedure until water runs clean. Install thermostat and
fill cooling system. Refer to (Cooling System Refill-
ing) for procedure.
REVERSE FLUSHING
Reverse flushing of the cooling system is the forc-
ing of water through the cooling system, using air
pressure in a direction opposite to that of the normal
flow of water. This is only necessary with dirty sys-
tems and evidence of partial plugging.
CHEMICAL CLEANING
One type of corrosion encountered with aluminum
cylinder heads is aluminum hydroxide deposits. Cor-
rosion products are carried to the radiator and depos-
ited when cooled off. They appear as dark grey when
wet and white when dry. This corrosion can be
removed with a two part cleaner (oxalic acid and
neutralizer) available in auto parts outlets. Follow
manufacturers directions for use.
ADJUSTMENTS
PROPER BELT TENSION
Satisfactory performance of the belt driven accesso-
ries depends on belt condition and proper belt ten-
sion. Refer to Accessory Drive Belt Inspection in this
section. There are two belt tensioning methods given
in order of preference:
²Belt tension gauge method.
²Torque equivalent method.
The belt tension gauge method usually requires the
vehicle to be raised on a hoist and the splash shield
removed.
TORQUE EQUIVALENT METHOD
Adjustable accessory brackets provided with a 13
mm (1/2 in.) square hole for a torque wrench can use
an equivalent torque value for belt adjustment.
Equivalent torque values for adjusting these acces-
sory drive belts are specified in the Belt Tension
Chart.
Fig. 29 Cooling System Pressure Cap
BELT TENSION CHART
ACCESSORY
DRIVE BELTGAUGE TORQUE
Power Steering
Pump and A/C
CompressorNew 135 lb. 121 N´m (90 ft.
lbs.)
Used 100 lb. 81 N´m 60 ft.
lbs.)
Generator New 135 lb. Gauge
adjustment
method only Used 100 lb.
PLCOOLING 7 - 23
CLEANING AND INSPECTION (Continued)